Kovalenko was born in St Petersburg, Russia. His father worked for the Russian intelligence service, but as a control officer this is closely guarded secret. His front was as a normal corporate executive. He had hoped to use his influence to get Sergei into the secret service, but was killed when Sergei was still a young boy.

Kovalenko is a recently retired Starfleet officer, and not by choice. A career helmsman, his career was cut short by a failure to reach the rank of commander. No one could offer any logical explanation for the promotion board results, and no appeal was successful. He is profoundly bitter about his expulsion from the service, and is eager to prove his effectiveness in the subsequent career.

He has never married and had few relationships, owing to his career service in Starfleet. He has never had a "shore" assignment, which might manifest an apprehensiveness with being planetside. His sole vice is the occaisional use of alcohol (vodka, of course).

Sergei is an avid reader of history and science. He has had few opportunities to engage in much of anything else over the years.